How do I recover data from a corrupt MAT-file?

When I attempt to load a MAT-file created in MATLAB 7.2 (R2006a), I receive the following error:

???Error using ==> load

Unable to read MAT file /home/$dir

File may be corrupt.

I, however, am able to view the variables in the MAT-file with the following command:

whos -file corruptMATFileName

I would like to recover this data. The MATZEROFIX file I found on MATLAB Central did not recover the data.

Answer 1

[MathWorks Support Team]

The issue might be caused by the presence of a corrupt zero-byte tag in the MAT-file. If this is the case, one might be able to extract the data from the MAT-file until a corrupt zero-byte tag is reached.

Please download the following SPLITMAT file in your current folder of MATLAB. Also, please ensure that the corruptMATFile is in the same current folder.

Then use the command as detailed below:

splitmat corruptMATFileName % Do not include the .mat extension

The above command will generate "n" MAT-files: corruptMATFileName_1.mat through corruptMATFileName_n.mat, each containing a variable contained in the original MAT-file.

If this command does not work, you may also try the following syntax to recover non-corrupted variables from the MAT-file:

>> load('<corrupted_file>.mat', '<uncorrupted_variable>');

[Ingrid]

thanks for posting this code, it worked great on my mat-file that I could not open anymore and I was able to recover the data that I needed. Recreating it would have taken a very long time so I am very happy that it worked although I do not know what caused the corruption of the file in the first place.

[James Tursa]

If the problem is caused by invalid variable or field names in the file, the following FEX submission might help as well:

https://www.mathworks.com/matlabcentral/fileexchange/42274-loadfixnames-loads-a-mat-file-fixing-invalid-names

[Walter Roberson]

I had no problem downloading the loadfixnames contribution by clicking on Download Zip.

[Esha Bhargava]

Alicia, please contact MathWorks Technical Support.

[Walter Roberson]

The tools you are using to work with potentially corrupt files are intended for -v5 and -v7 MATLAB files, and not for -v7.3 files. -v7.3 files are a customized HDF5 format; sometimes they can be examined with HDF5 tools.

[Walter Roberson]

If you attach the .fig and associated .m files, I can try running it through some tools I have been developing. No promises, though, as the tools are not designed for the case where the .fig is a corrupted .mat .